1. Technical Field
The field of this invention is vascular disease, particularly vascular diseases characterized by the presence of calcified vascular occlusions.
2. Background of the Invention
Vascular occlusions, which may be partial or total occlusions, play a prominent role in many types of vascular disease. Many vascular occlusions encountered in the treatment of vascular disease are characterized by having a mineral component, i.e. they are calcified. Calcified vascular occlusions, both partial and total, are found in both peripheral and coronary vascular disease A variety of different protocols have been developed for treating vascular diseases characterized by the presence of partial or total occlusions. Such treatment methodologies generally involve mechanical removal or reduction of the size of the occlusion, and include: bypass surgery, balloon angioplasty, mechanical debridement, atherectomy, and the like.
Despite the plethora of different treatment strategies that have been developed for the treatment of vascular diseases associated with vascular occlusions, there are disadvantages associated with each technique, such as tissue damage, invasiveness, etc. For example, restenosis is a common complication that results in arteries in which occlusions have been mechanically removed.
Calcified vascular occlusions pose significant challenges to currently employed treatment methodologies. For example, where the target vascular occlusion is a total occlusion, it is difficult if not impossible to pass a guidewire through the occlusion, which step is required for many of the currently used procedures. While bypass grafts are sometimes available as alternatives in such instances, bypass procedures have their own risks and complications. Furthermore, if there is no appropriate anastomosis site available, amputation is often the only alternative.
As such, there is continued interest in the development of endovascular methods of treating vascular occlusions. Of particular interest would be the development of methods and devices suitable for use in the treatment of calcified vascular occlusions.
Relevant Literature
U.S. patents of interest include: U.S. Pat. Nos. 4,445,892; 4,573,966; 4,610,662; 4,636,195; 4,655,746; 4,690,672; 4,824,436; 4,911,163; 4,976,733; 5,059,178; 5,090,960; 5,167,628; 5,195,955; 5,222,941; 5,370,609; 5,380,284; 5,443,446; 5,462,529; 5,496,267; 5,785,675; and 5,833,650. See also: Koltun et al., Arch. Surg. (August 1987) 122:901-905; Olin et al., Ann. Emerg. Med. (November 1988) 17:1210-1215; Hargrove et al., Surgery (December 1982) 92:981-993; and Rickard et al., Cardiovascular Surg. (December 1997) 5:634-640. See also PERIPHERAL ENDOVASCULAR INTERVENTIONS, 2nd ed. (White and Fogarty eds., Springer, N.Y.)(1996) pp 565-576.
Multi-lumen catheter devices and methods for their use in enhancing fluid flow through a vascular site occupied by a vascular occlusion are provided. The subject catheter devices include at least a first, second and third lumen, where: (a) the first lumen is used for delivery of an acidic dissolution solution to the vascular site; (b) the second lumen is used for delivery of a buffer solution to the vascular site; and (c) the third lumen is used for removal of fluid from the vascular site. In many preferred embodiments, the first, second and third lumens are coaxial. In practicing the subject methods, the vascular site is flushed simultaneously with an acidic dissolution fluid and a buffer solution, where flushing is carried out in a manner such that only a surface of the vascular occlusion is contacted with the acidic dissolution fluid and the remainder of the vascular site is not contacted with fluid having a pH that is lower than about 4. Flushing is carried out in this manner for a period of time sufficient for fluid flow through the vascular site to be enhanced, e.g. increased or established. Also provided are systems and kits comprising the subject catheter devices. The subject catheter devices, kits, systems and methods find use in the treatment of a variety of different vascular diseases characterized by the presence of calcified vascular occlusions, including peripheral and coronary vascular diseases.